Conventionally, wireless power supply systems have been known in which power is supplied while a power supply coil and a power receiving coil are placed facing each other in a wireless manner. In such wireless power supply systems, when vibration is added to the power supply side during power supply due to an earthquake or the like, the position of the power supply coil changes.
For example, in a wireless power supply system that supplies power to a power storage apparatus mounted on a vehicle such as an electric vehicle, a power supply apparatus is installed on the ground. In this case, when an earthquake occurs or when a large vehicle passes by, vibration occurs in the power supply apparatus and the position of the power supply coil changes. When a wireless power supply system to supply power to a portable device is mounted on a mobile unit such as a vehicle, vibration occurs and the position of the power supply coil changes as the mobile unit moves.
When the position of the power supply coil changes during power supply, coupling between the power supply coil and the power receiving coil changes, causing excessive output or an increase in magnetic flux leakage.
Conventionally, wireless power supply systems configured to stop a charging section mounted on the vehicle when an unexpected situation such as an earthquake occurs have been known (e.g., FIG. 10 in Patent Literature (hereinafter, referred to as “PTL”) 1). When an unexpected situation occurs, the wireless power supply system of PTL 1 performs control of stopping power supply to a power storage apparatus by ECU. When resumption of the power supply is impossible, the power receiving side notifies the power supply side through communication that the power supply stops. Thus, the technique in PTL 1 can reduce excessive output or an increase in magnetic flux leakage associated with a change in the coupling between the power supply coil and the power receiving coil.